(CNN) -- Manchester City's dreams of an English domestic treble were left in ruins Sunday as they fall victim for the second year in a row to Wigan in the FA Cup.

Last year's defeat in the final at Wembley preceded the departure of Roberto Mancini, but in many ways the 2-1 quarterfinal exit at their own Etihad Stadium was an even bigger giant killing feat.

City under Manuel Pellegrini won the English League Cup at Wembley last weekend and are battling for the Premier League title, while Wigan have dropped to the second flight after being relegated following their own cup triumph.

With fortunes revived under Uwe Rosler, who was a favorite son at Manchester City as a player, Wigan took the game to their illustrious opponents and led 2-0 through a first half penalty from Jordi Gomez and an early strike after the break from James Perch.

City hit back with a goal from Samir Nasri, but in a frantic finish were unable to equalize as Wigan held out.

Rosler, who has lifted Wigan from mid-table in the Championship to challenging for a playoff spot since taking over in December, hailed a "tremendous performance" from his side.

"Obviously a lot of things have been written (about his return to City) and I kept my emotions under control and focused on the job in hand, but the players made it easy for me the way they performed," he told BBC Radio Five Live.

A stunned Pellegrini must now get his team ready for a midweek trip to Barcelona, trailing 2-0 from the first leg in the Champions League last 16 tie.